Animal Crossing - You have a house in a little community and you keep it up by doing tasks for the other citizens and pulling up weeds. It's all really cute.

The World Ends With You - This one is Teen rated, but it's mostly for dealing with life and death type concepts. It's an action RPG where you collect pins and clothing and fight monsters in a very fashionable part of Japan.

Okamiden - RPG where you ride a dog and do things by drawing. I haven't actually played it, but it's very highly regarded among DS games.

Retro Game Challenge - This game kind of recreates old video games without infringing anyone's copyrights. You play them for goals within the game, and collect fake gaming magazines with real tips and codes for these fake games. I thought it was really fun, but it might be past RS's age. The games it recreates are pretty old school.

Scribblenauts and Super Scribblenauts - Solve puzzles by bringing things into the game with words! You can type out "helicopter" and a helicopter will appear. It's pretty fun!

Picross and Picross 3D - These are puzzle games in which you use the clues to fill in blocks that make little pictures. It's been compared to sudoku, except the numbers make pictures. I personally love Picross (and Picross 3D) and put an enormous amount of time into it. I ruined my DS touch screen playing so much Picross in dusty Iraq.

Etrian Odyssey 1, 2, 3 - These are first-person dungeon crawls that are really colorful and you can make your party however you like, and you draw the map of where you are yourself. They're rated E something but they're kind of difficult.

I added links to each game's article on Giant Bomb's game wiki so you can get more information about them. Also, I tried to stick with E or E10+ rated games. If you're cool with Teen rated games, I have a lot more recommendations.

I'm seconding Animal Crossing, TWEWY and Scribblenauts. If he likes Pokémon, TWEWY is probably the closest in premise. It's like Pokémon with a PhD and a big dose of coolness. AC is a bit love-it-or-hate-it, but I love it. Scribblenauts is unbridled fun.

_________________Moon - "This is the best recipe in the history of recipes forever."

Okamiden is a forking delight. It's a sequel to a PS2 game, but it's a bit easier and, I think, more child-friendly. I also second the Animal Crossing recommendation.

Chibi-Robo! Park Patrol is a game where you play a teeny robot who tends to an enormous garden, rides a bicycle, is a DJ, fights bad guys, and makes friends with toys who need your help. Here are twotrailers for it. It's part of a series that started on the GameCube, and there is a third game that only came out in Japan that is for the DS. This is one of my favourite series.

If he likes puzzles, the Professor Layton games are delightful. There is a whole series of them, but here is a trailer for the first one. Some of the puzzles can be difficult, but you can use "hint coins" to get help.

I FORGOT CHRONO TRIGGER. This game is a classic from the SNES and the DS version of it is really great. It's a turn-based RPG with a great story, and it's longer - about as long as a Pokemon game, which may be a good or bad thing depending on if he likes to spend that much time on a game. Trailer.

Also like brian, if you are okay with games that are rated higher I have more recommendations!

Also also, I look like an asparagus because I missed that solipsistnation mentioned Professor Layton already. Sorry!

_________________"I will rip out your IV and other roman numerals." - pandacookie"The one thing I would not do for Aubrey Plaza is harm a baby, by the way." - strawberryrock

Someone came in today asking about Poptropica Adventures for DS. She said her 8 year old and his friends are nuts for it. I'm not too familiar with the game but it's worth a look. Just scanning through it looks a bit childish for a 10 year old but you'd be the better judge of that.

_________________"...anarchists only want to burn cars and punch cops."- nickvicious"We'll be eating our own words 30 years from now when we're demanding our legislators outlaw aerosol-based cyber dildo-wielding death holograms."- Brian

I've just finished Ghost Trick. It's a really good, really silly puzzle game about using ghost powers to solve puzzles and a mystery. It's got a Phoenix Wright-esque vibe to its humour and has some of the best animation I've seen in a game, some of which actually made me laugh aloud. The ending is so ridiculously deranged that it, also, made me laugh.

It's not a short game, but it left me wanting more.

_________________Moon - "This is the best recipe in the history of recipes forever."